I have an ubuntu 18.04 that has a "ASUS PCE-AC55BT B1 AC1200 Wireless Bluetooth 4.2 PCIe/Mpcie Adapter." The wifi and bluetooth were working fine for a couple months, but recently the bluetooth has broken (the wifi still works).
I am pretty sure I have tried every result on the first 3 pages of Google when searching this problem, but I cannot figure out why the bluetooth is not working. I have spent over 8 hours trying to fix this very annoying problem, so I would be very thankful if anyone can help.
Here is some more information and things I have tried.
I have a dual boot pc (Windows 10 and Ubuntu 18.04). The bluetooth does not work on either and the wifi works on both. This makes me think there is something wrong on a very low level (hardware or bios drivers).
I have even tried buying a replacement for my old wifi/bluetooth adapter of the same model because I thought maybe the bluetooth had broke for some reason. The new one also has the same problem. I have tried moved the card into a different pci slot with no luck. This means the hardware is not broken.
The problem seems to lie in the fact that no bluetooth adapter is detected. When I do rfkill list, I only see Wireless LAN, but no bluetooth.
0: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
When I run systemctl status bluetooth, I get
bluetooth.service - Bluetooth service
Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)
Active: inactive (dead)
Docs: man:bluetoothd(8)
I have also confirmed I have the newest versions of bluez, bluetooth, and bluez-tools.
When I try to run Bluetooth Manager, I get an error
Bluez daemon is not running, blueman-manager cannot continue. This probably means that there were no Bluetooth adapters detected or Bluetooth daemon was not started.
I tried starting the bluetooth daemon with both of these lines, but systemctl status bluetooth still shows bluetooth as inactive (dead) after these commands.
sudo service bluetooth restart
sudo /etc/init.d/bluetooth start
[ ok ] Starting bluetooth (via systemctl): bluetooth.service.
I am honestly not even sure what to try anymore since nothing seems to be working. The weirdest part to me is that the bluetooth was working fine for a couple months and then it stopped working. The only thing I can remember changing is setting acpi=force in /etc/default/grub, but I removed this later after I found the bluetooth wasn't working. I am not sure if this is correlated since I didn't test the bluetooth right before/after.